package com.lx.gulimall.cart.interceptor;

import com.lx.common.constant.AuthServerConstant;
import com.lx.common.constant.CartConstant;
import com.lx.common.to.MemberRespVo;
import com.lx.gulimall.cart.vo.UserInfoTo;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * @author lixun Email:lx3027@126.com
 * @create 2021-08-09 11:26
 * 在执行目标方法之前，判断用户的登录状态 并封装传递给controller目标请求
 */
@Component
public class CartInterceptor implements HandlerInterceptor {

    public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();

    /**
     * 业务执行之前
     *
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request,
                             HttpServletResponse response,
                             Object handler) throws Exception {
        UserInfoTo userInfoTo = new UserInfoTo();
        HttpSession session = request.getSession();
        MemberRespVo member = (MemberRespVo) session.getAttribute(AuthServerConstant.LOGIN_USER);
        if (member != null) {
            // 用户登录了
            userInfoTo.setUserId(member.getId());
        }
        Cookie[] cookies = request.getCookies();
        if (cookies != null && cookies.length > 0) {
            for (Cookie cookie : cookies) {
                // 如果请求还携带了临时用户的信息，临时用户的数据也要封装起来
                String name = cookie.getName();
                if (CartConstant.TEMP_USER_COOKIE_NAME.equals(name)) {
                    userInfoTo.setUserKey(cookie.getValue());
                    userInfoTo.setTempUser(true);
                }
            }
        }
        // 如果没有临时用户，则需要分配一个临时用户
        if (StringUtils.isEmpty(userInfoTo.getUserKey())) {
            String uuid = UUID.randomUUID().toString();
            userInfoTo.setUserKey(uuid);
        }
        // 方法执行之前，将数据放到ThreadLocal中
        threadLocal.set(userInfoTo);
        return true;
    }

    /**
     * 业务执行之后
     *
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(
            HttpServletRequest request,
            HttpServletResponse response,
            Object handler,
            ModelAndView modelAndView) throws Exception {

        UserInfoTo userInfoTo = threadLocal.get();
        // 如果登录用户不是临时用户，就为其添加cookie
        if (!userInfoTo.getTempUser()) {
            Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
            cookie.setDomain("gulimall.com");
            cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
            // 解决跳转页面之后，无法保存cookie
            cookie.setPath("/");
            response.addCookie(cookie);
        }

    }
}
